Submission #398593

#	Time	Username	Problem	Language	Result	Execution time	Memory
398593		richyrich	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	15 ms	19100 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const ll MOD = 1e9+7;
const ll N = 2e5+10;
const ll inf = 1e9+100;
const double eps = 1;
int n, a[N];
set<int> L[N], R[N];
ll ans;
bool used[N];
long long count_swaps(std::vector<int> s) {
	/*for(int c : s) printf("%d ", c);
	printf("\n");*/
	ans = 0;
    n = s.size();
    for(int i = 1;i <= n;i++) {
    	a[i] = s[i-1];
    	if(a[i] < 0) L[-a[i]].insert(i);
    	else R[a[i]].insert(i);
    }
    /*for(int i = 1; i <= 2; i++) {
    	printf("left %d:", i);
    	for(int c : L[i]) printf("%d ", c);
    	printf("\n");
    }
    for(int i = 1; i <= 2; i++) {
    	printf("right %d:", i);
    	for(int c : R[i]) printf("%d ", c);
    	printf("\n");
    }*/
    for(int i = 1; i <= n; i++){
    	if(used[i]) continue;
    	int pos;
    	if(a[i] < 0) {
    		pos = *R[-a[i]].begin();
    		L[-a[i]].erase(i);
    		R[-a[i]].erase(pos);
    		ans += pos - i - 1;
    		used[pos] = used[i] = 1;
    	}
    	else {
    		pos = *L[a[i]].begin();
    		R[a[i]].erase(i);
    		L[a[i]].erase(pos);
    		ans += pos - i;
    		used[pos] = used[i] = 1;
    	}
    }
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15